Au nano-urchins enabled localized surface plasmon resonance sensing of beta amyloid fibrillation.

Early stage detection of neurodegenerative diseases such as Alzheimer's disease (AD) is of utmost importance, as it has become one of the leading causes of death of millions of people. The gradual intellectual decline in AD patients is an outcome of fibrillation of amyloid beta 1-42 (Aβ 1-42 ) peptides in the brain. In this paper, we present localized surface plasmon resonance (LSPR) based sensing of Aβ 1-42 fibrillation using Au nano-urchins. Strongly localized field confinement at the spiky nanostructures of nano-urchin surfaces enables them to detect very low concentrations of Aβ 1-42 . In addition, the LSPR peak of Au nano-urchins, which is very sensitive to ambient conditions, shows significant responses at different fibrillation stages of Aβ 1-42 . Reduction in LSPR peak intensity with an increase in the fibrillation is chosen as the sensing parameter here. This paper in this context provides LSPR based highly sensitive, label-free and real-time sensing of Aβ 1-42 fibrillation that is highly advantageous compared to the existing techniques which require binding additives or fluorescent biomarkers.